spartan 1w vs arctic s3 beam divergence

[ZapU]

I'm pretty sure that the axis with the lowest diameter at aperture is the fast axis, that is why it diverges more and why beam correction optics work by expanding it to make it less divergent.

View attachment 29271

I guess with the casio diode we need to be specific about which axis we are asking about for mRad. Off course, I measured the aperture at the its widest point, not even considering axis. That seems to be a common assumption (see Spartan X figure of 3.5). I was in error (n00b!). But for the sake of discussion, if you take the long measurement at the aperture, 5mm, and the narrow one at the target (lets say about 2mm), then the mRad for that would be 0.49999995833333954.
Even when you plug in 1mm as the aperture in the original calculation, then I get a mRad of 1.9999973333.

This distance is too short to calculate accurately, I agree with DrSid, must make longer distance measurement. Will do soon.

 

[ZapU]

OK, set up a quick measurement (tape measured).
Distance 310 feet (couldn't quite get 100 meters, best straight shot on my property)
Beam diameter (length) 8 inches. Put in aperture of .040 inches for grins.
Arctic mRad 2.1397816804
Spartan mRad 3.5462351343 (from Spartan X figures)

DrSid, you are correct, 1.5 not possible

graviton, as to your original question, lower is better. Arctic wins! :spank:


Would I buy another Arctic? No, not for $300 + shipping. I would recommend one of the fine kits available on this forum.

 

[DrSid]

Anyway it's much closer then I thought it would be. It was a rushed statement from me it seems.

Still in such case it might be only bad focus, not minimal possible divergence.

 

[ZapU]

Anyway it's much closer then I thought it would be. It was a rushed statement from me it seems.

Still in such case it might be only bad focus, not minimal possible divergence.

What are you saying is bad focus? Since my Arctic IS focusable, I sharpened it to the best focus at 310 feet.

 

[DrSid]

Yep .. but Spartan is not (AFAIK).

 

[Trevor]

graviton, as to your original question, lower is better. Arctic wins! :spank:

So, by your method of determining the better laser, the Arctic is better in terms of build quality, output, and divergence!

-Trevor

 

[ZapU]

So, by your method of determining the better laser, the Arctic is better in terms of build quality, output, and divergence!

-Trevor

gravitron's original question was divergence, which the Arctic was much better, not what was the better laser.

Where do you see where I said it was better in build quality or output? Are you trying to discredit me simply because I measured the Arctic better in divergence than the mighty Spartan? Facts are facts. Deal with it.

 

[Spartan X]

The Arctic uses a Aixiz 445nm Collimator lens...nothing to special outside of the DIY build lands. So the divergence is going to be the same as any build using that lens.

The DL Spartan does not use a similar lens, it's of their own design. It's fixed focus, and non-adjustable. I'm sure I would get better results if I tested from a closer distance.

 

[Trevor]

gravitron's original question was divergence, which the Arctic was much better, not what was the better laser.

Where do you see where I said it was better in build quality or output? Are you trying to discredit me simply because I measured the Arctic better in divergence than the mighty Spartan? Facts are facts. Deal with it.

No, you said lower is better. So I made an obviously facetious statement.

You, sir, need a sense of humor.

-Trevor

 

[ZapU]

No, you said lower is better. So I made an obviously facetious statement.

You, sir, need a sense of humor.

-Trevor

gravitron is a new member. I don't know if he knew if lower numbers were better or not. In this forum of nearly countless "Arctics are crap" postings, I did not see your statement as facetious. Certainly seemed like a put down to me. Posting anything positive about the Arctic always seems to get a negative reply. I have a sense of humor, but it wears thin from so much hostile attitude.

Sarcasm sensor triggered :lasergun:

 

[drummerdimitri]

I'm pretty sure that the axis with the lowest diameter at aperture is the fast axis, that is why it diverges more and why beam correction optics work by expanding it to make it less divergent.

View attachment 29271

Is that how you're supposed to measure divergence? should you find the width of the line at the aperture and the measure it's width after some distance? Why would measure it's height at the aperture and then measure it's width to find divergence? I'm confused

 

[DrSid]

Best way is to measure at large distance (100m) and then neglect aperture size (it plays small role in such case).

 

[mikeeey]

here's my results for my Spartan 447nm 1W:

Apature size: 4mm
10 feet: 10mm
20 feet: 18mm

According to Pseudonomen's calculator, my Spartan's divergence is 2.62mRad.

Btw I've measured the long side of the dot, facing horizontal, I suppose that would only make sense.

 

[ZapU]

here's my results for my Spartan 447nm 1W:

Apature size: 4mm
10 feet: 10mm
20 feet: 18mm

According to Pseudonomen's calculator, my Spartan's divergence is 2.62mRad.

Btw I've measured the long side of the dot, facing horizontal, I suppose that would only make sense.

Check out Grix's post on the previous page. Seems most of us are measuring it wrong, you should use the short side. This is the picture in his post.

The best way is to measure at a long distance, say 100M.

 

[WarpWar]

I am having an issue with the beam diameter, I will probably post a thread in the "help" section, but I thought this was a good place to

mention it.

My Spartan 1W laser has begun to have "beam expansion" issues.
from when I first ran it for a few seconds to now, it has had a burning smell (if you smell the tube where you insert the batteries). I

didn't think this was a big deal since it appeared to run fine, the beam looked good.

but tonight after doing some "skyshining" it appears that the dot expands as you run it, it definitely didn't do this before.

@15 feet:
when first turned on, it makes a bar that is 2cm X 0.3cm
within a minute, it expands to 2cm X 1cm
by three it appears to have stopped at 2cm X 1.5cm.

it has maybe 20 minutes of run time total and I have never run it for more than 4 to 5 minutes at a time.

It at 15 feet looks similar in size to a picture taken by a guy at 47 feet, but mine cuts off part of the beam

There is an image of someone else's taken at ~20 feet and his looks much better as well

attached images from left to right: mine @ 15feet, other persons @ 47 feet, other persons @ 20 feet.

I feel something has gone wrong with mine, and I should return it, do you guys agree?

 

[DrSid]

That middle picture is from 400mW spartan. It's rather unclear how they did it, because we know there is no special optics or anything inside. Maybe the diode is different.
As for your problem, It may be even from geometry change because of temperature, or the diode changes modes (because of temperature again).